It is likely written as "BAL unk" in a police report or arrest record, or copied from these papers to the court record. BAL in this context probably means "blood alcohol level". "Unk" is a standard abbreviation for "unknown". A "BAL unk" in a court situation likely means no blood was drawn right after the incident, so there was no blood specimen to submit to the laboratory to test it.
As an example: If a drunk driver commits a hit and run which results in bodily injury, but the driver is not found and arrested until hours after the crime, no blood test would be done because during every hour the blood alcohol content or level reduces/declines. Therefore, the police could only report to the court "BAL unk".
Define; csc 2-unk act-unk assail-unk age-F
Unknown odor.
unk
Unk was born on 1982-03-28.
Unk White was born in 1900.
Unk White died in 1986-03.
Show Out - Unk song - was created in 2008-09.
UNK
no
uncle
They cover your unk
Unlawful/unk/IPOS/WO/rxsch.1v